Chemical and natural options

Weeds generally are so persistent that they will appear in areas of the garden where efforts to introduce certain cultivated plants may fail.

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Deep shaded places, dry embankments, poor drainage, acid or alkaline soil conditions - each of these demands a careful choice of ground cover, be it a carpet-forming or sucker type, hummock or clump-forming.

For practicality, I bypass annual or biennial plants, and certain herbaceous perennials too because year-round permanence is required. So, it's down to the evergreen colonising perennials for high density cover.